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[Patch, Fortran] PR25071 - give an error if character len of actual argument too short
- From: Tobias Burnus <burnus at net-b dot de>
- To: "'fortran at gcc dot gnu dot org'" <fortran at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 03 May 2007 21:48:50 +0200
- Subject: [Patch, Fortran] PR25071 - give an error if character len of actual argument too short
:ADDPATCH fortran:
This fixes part* of PR25071. An error is printed if it is known at
compile time that the character length of the actual argument is shorter
than the one of the formal argument.
Additionally, if the formal/dummy argument is a pointer or allocatable
then the length ("type parameter") needs to match exactly.
We give in both cases an error as NAG f95 does. g95 gives a warning for
the first and an error for the second. ifort and sunf95 gives an error
for the first and accepts the second without any notice.
>From the Fortran standard:
"12.4.1.2 Actual arguments associated with dummy data objects"
"The type parameter values of the actual argument shall agree with the
corresponding ones of the dummy argument that are not assumed or
deferred, except for the case of the character length parameter of an
actual argument of type default character associated with a dummy
argument that is not assumed shape."
"If a scalar dummy argument is of type default character, the length len
of the dummy argument shall be less than or equal to the length of the
actual argument. The dummy argument becomes associated with the leftmost
len characters of the actual argument. If an array dummy argument is of
type default character and is not assumed shape, it becomes associated
with the leftmost characters of the actual argument element sequence
(12.4.1.5) and it shall not extend beyond the end of that sequence."
"If the dummy argument is a pointer, the actual argument shall be a
pointer and the nondeferred type parameters and ranks shall agree. If a
dummy argument is allocatable, the actual argument shall be allocatable
and the nondeferred type parameters and ranks shall agree."
Build and regression tested with no failures but
gfortran.fortran-torture/execute/st_function.f90 (PR31095).
Ok for the trunk?
Tobias
* The unfixed part is to do the same check for arrays; here one has to
check the storage extent.
2007-05-03 Tobias Burnus <burnus@net-b.de>
PR fortran/25071
* interface.c (compare_actual_formal): Check character length.
2007-05-03 Tobias Burnus <burnus@net-b.de>
PR fortran/25071
* gfortran.dg/char_length_3.f90: New test.
* gfortran.dg/char_result_2.f90: Fix test.
Index: gcc/fortran/interface.c
===================================================================
--- gcc/fortran/interface.c (revision 124381)
+++ gcc/fortran/interface.c (working copy)
@@ -1369,6 +1369,34 @@ compare_actual_formal (gfc_actual_arglis
return 0;
}
+ if (a->expr->ts.type == BT_CHARACTER
+ && a->expr->ts.cl && a->expr->ts.cl->length
+ && a->expr->ts.cl->length->expr_type == EXPR_CONSTANT
+ && f->sym->ts.cl && f->sym->ts.cl && f->sym->ts.cl->length
+ && f->sym->ts.cl->length->expr_type == EXPR_CONSTANT)
+ {
+ if (mpz_cmp (a->expr->ts.cl->length->value.integer,
+ f->sym->ts.cl->length->value.integer) < 0)
+ {
+ if (where)
+ gfc_error ("Character length of actual argument shorter "
+ "than of dummy argument '%s' at %L",
+ f->sym->name, &a->expr->where);
+ return 0;
+ }
+
+ if ((f->sym->attr.pointer || f->sym->attr.allocatable)
+ && (mpz_cmp (a->expr->ts.cl->length->value.integer,
+ f->sym->ts.cl->length->value.integer) != 0))
+ {
+ if (where)
+ gfc_error ("Character length mismatch between actual argument "
+ "and pointer or allocatable dummy argument "
+ "'%s' at %L", f->sym->name, &a->expr->where);
+ return 0;
+ }
+ }
+
/* Satisfy 12.4.1.2 by ensuring that a procedure actual argument is
provided for a procedure formal argument. */
if (a->expr->ts.type != BT_PROCEDURE
Index: gcc/testsuite/gfortran.dg/char_length_3.f90
===================================================================
--- gcc/testsuite/gfortran.dg/char_length_3.f90 (revision 0)
+++ gcc/testsuite/gfortran.dg/char_length_3.f90 (revision 0)
@@ -0,0 +1,30 @@
+! { dg-do compile }
+! PR fortran/25071
+! Check if actual argument is too short
+!
+ program test
+ character(len=10) :: x
+ character(len=30), target :: y
+ character(len=30), pointer :: ptr
+ character(len=30), allocatable :: alloc(:)
+ ptr => y
+ call foo(x) ! { dg-error "actual argument shorter than of dummy" }
+ call foo(y)
+ call foo(ptr)
+ call bar(ptr) ! { dg-error "Character length mismatch" }
+ allocate(alloc(1))
+ call arr(alloc) ! { dg-error "Character length mismatch" }
+ contains
+ subroutine foo(y)
+ character(len=20) :: y
+ y = 'hello world'
+ end subroutine
+ subroutine bar(y)
+ character(len=20),pointer :: y
+ y = 'hello world'
+ end subroutine
+ subroutine arr(y)
+ character(len=20),allocatable :: y(:)
+ y(1) = 'hello world'
+ end subroutine
+ end
Index: gcc/testsuite/gfortran.dg/char_result_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/char_result_2.f90 (revision 124381)
+++ gcc/testsuite/gfortran.dg/char_result_2.f90 (working copy)
@@ -42,9 +42,11 @@ program main
character (len = 80) :: text
character (len = 70), target :: textt
character (len = 70), pointer :: textp
+ character (len = 50), pointer :: textp2
a = 42
textp => textt
+ ! textp2 => textt(1:50) ! needs fixed PR31803
call test (f1 (textp), 70)
call test (f2 (textp, textp), 95)
@@ -53,7 +55,7 @@ program main
call test (f5 (textp), 140)
call test (f6 (textp), 29)
- call indirect (textp)
+ ! call indirect (textp2) ! needs fixed PR31803
contains
function f3 (string)
integer, parameter :: l1 = 30
@@ -93,7 +95,7 @@ contains
call test (f1 (textp2), 50)
call test (f2 (textp2, textp), 65)
call test (f3 (textp2), 85)
- call test (f4 (textp2), 192)
+! call test (f4 (textp2), 192) ! invalid: actual leng 50 < formal len 70
call test (f5 (textp2), 100)
call test (f6 (textp2), 9)
end subroutine indirect